Recently, transparent conductive thin films have been used for various electronic devices, such as organic light emitting diodes, displays, solar cells, or the like. Such transparent conductive thin films are used mostly as electrodes to make an electrical connection in many electronic devices. Transparent conductive electrodes (TCEs) using transparent conductive thin films are applied to transparent film heaters (TFHs) based on the Joule heating. Such transparent film heaters are used in aircraft displays, liquid crystal display (LCD) panels, car window defrosters, or the like. A conductive oxide used largely in transparent film heaters is indium tin oxide (ITO) having excellent conductivity and transparency. However, indium tin oxide (ITO) has brittleness in nature, and thus is limited in applications to flexible electronic devices. In addition, scarcity of indium materials is a cause of an increase in manufacturing cost for transparent film heaters.
To solve the above-mentioned problems of indium tin oxide (ITO), transparent film heaters using carbon nanotubes (CNTs) have been suggested as disclosed in the following patent document. However, although carbon nanotubes (CNTs) may substitute for indium tin oxide (ITO) in terms of mechanical flexibility and thermal response, they have a large sheet resistance and require a high driving voltage.
Therefore, there is an imminent need for a solution for the above-mentioned problems occurring in the conventional transparent film heaters.